This is a considerable advance for research that lacks a good study model: firstly it is almost impossible to observe directly in utero in women and secondly the brain is the organ for which the transposition of animal models to humans is the most delicate.

The researchers "grew" these mini-brains from human stem cells. After six months, the electroencephalographic activity of these organoids appeared comparable to that of premature children aged 25 to 39 weeks.

This is a scientific achievement: these organoids could be very good models to study psychiatric diseases.

But it raises ethical questions: are these organoids conscious? What attitude should be adopted? Today no regulation is capable of answering these questions.